The Contractor shall exert its best efforts to continue work begun under predecessor contract, in further development, refinement, and application of an in vitro cellular cytotoxicity test originally developed by the principal investigator. Specific studies of selected tissue culture cell lines will be conducted in order to achieve the following objectives: The identification of sarcoma specific antigens; The demonstration of immune reactions to these antigens in the cancer patients and normal controls; and The participation in collaboration projects to determine which of the reactions are potentially detecting virus-specific and/or tumor specific antigens.